I've just started mining this week, and have tried to optimise my set up myself, but I'm still not achieving what others are reporting on my present set up.

I'm mining off a ATI Radeon HD5770 with 1GB memory, and this is not a dedicated card - its running my PC, too. I'm using the phatk kernel on the phoenix miner. Vectors, hd5xxx+ and fastloop are all on. Aggression is 8, and worksize is 128. I've joined the 50BTC pool, but for no good reason. If there is somewhere better to be, I'm open to suggestions there.

Some questions:

• At present, I'm getting ~185MH/s when the card is working, but not for a lot of the time. My average is setting around 60MH/s. I've heard from others that it's possible to get +20MH/s on my card, on similar settings, so I think I might be missing something crucial here. I am also curious as to why I'm only mining 30% of the time.
• I'm getting about 18-20% of my results rejected, too, and from what I understand, the aim here is to be at least under 6-8%. Any ideas as to what is letting me down on this count?

Many thanks!